Incremental chairman Chris Cronin said on Wednesday there would be no material synergies from combining the two companies and that the hostile offer "materially" undervalued the oil producer.
"Incremental has built a substantial portfolio of high-quality, near-term production opportunities based on discovered resources under attractive fiscal terms," Cronin said in the company's target statement.
"In contrast, Cooper offers a smaller, declining production base combined with higher-risk and higher-cost international exploration areas of relatively less attractive fiscal terms."
Cooper is offering a choice of 3.1 of its own shares for each Incremental share, or 50 cents cash and 1.9 Cooper shares for each Incremental share.
The all-scrip bid values Incremental at about $76 million, while the scrip and cash alternative values the oil producer at about $86 million based on Cooper's closing price of 31 cents.
Incremental shares on Wednesday closed three cents lower at 87 cents.
Independent expert KPMG, which was commissioned by Incremental to compile a report on the offer, concluded the bid was not fair and valued the target's shares at between $3.39 to $4.18 each.
"In our view, Incremental can be set apart from other mid-cap oil and gas companies by its ability to achieve successful growth in reserves and maintain a dividend-paying regime whilst also largely shielding investors from high-risk, early stage exploration activities," KPMG said in its report.
The junior oil sector is facing a period of consolidation after the merger of ARC Energy Ltd and Australian Worldwide Exploration, and Roc Oil Company Ltd's bid for Anzon Australia Ltd.
A combined Incremental and Cooper will produce more than 2,000 barrels of oil a day and hold assets in Australia, Turkey, Indonesia, Tunisia and United States.
